Doctorfish
(Acanthurus chirurgus)
Classification
General data
Acanthurus chirurgus, commonly called doctorfish or doctorfish tang in English and barbero rayado or cirujano rayado in Spanish, is a tropical marine fish common in the Atlantic Ocean.
Description
Reaching a maximum size of 39 centimetres (15 in) and 5.1 kilograms (11 lb), Acanthurus chirurgus gets its common name for the structures called scalpels, which are found on either side of the caudal peduncle. The scalpel is used during fights with other doctorfish and as a defense mechanism against predators. Its coloration generally varies from blue-gray to dark brown. 10 to 12 vertical bars are always present but often faint. The edges of the caudal, dorsal, and anal fins are blue. There is also a faint blue ring that can be seen encircling the scalpel on either side.
There is a black morph, as well, but it is neither a subspecies nor a regional mutation. It has only been documented a limited number of times.
Range and habitat
The fish is typically found among rocky outcrops and coral reefs. Its distribution includes the Atlantic from Massachusetts to Brazil and the tropical west coast of Africa.
It has the largest distribution of its genus of 38 species.